The Japan Meteorological Agency forecast extreme heat across northern Japan and the rest of the country for Thursday [1].
This widespread temperature spike increases the risk of heat-related illnesses and disrupts daily activity in major urban centers and rural regions alike.
Heat alerts have been issued for 26 prefectures [1]. In Nagasaki, the region has been under a heat alert for 10 consecutive days [1].
Warm air aloft and strong sunshine are driving temperatures higher across the archipelago [2, 3]. This weather pattern has led to the first midsummer days of the year for five cities: Obihiro, Kitami, Morioka, Tokyo, and Hiroshima [1].
Predicted maximum temperatures for several cities reached 35 °C, including Tokyo, Obihiro, and Kitami [3]. Sapporo was expected to reach a maximum of 32 °C [3].
While heat dominates the forecast, atmospheric instability is creating other risks. The Japan Meteorological Agency said sudden thunderstorms were possible in the Kanto region [1, 2, 3]. Residents in eastern Japan are advised to monitor changing sky conditions as these storms can develop rapidly, creating hazards alongside the extreme heat [2, 3].
“Heat alerts have been issued for 26 prefectures.”
The simultaneous occurrence of extreme heat in northern regions like Hokkaido and the risk of sudden thunderstorms in the Kanto region indicates high atmospheric instability. The prolonged nature of the heat alerts, particularly the 10-day streak in Nagasaki, suggests a persistent high-pressure system that may strain local energy grids and public health resources.
